Differential susceptibility of peripheral blood CD5 + and CD5 − B cells to apoptosis in chronic hepatitis C patients

• Published in: Biochemical and biophysical research communications 2009-11, Vol.389 (3), p.512-515
• Main Authors: Mizuochi, Toshiaki, Ito, Masahiko, Takai, Kenji, Yamaguchi, Kazunari
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Apoptosis; Apoptosis - immunology; B cells; B-Lymphocytes - immunology; CD5; CD5 Antigens - immunology; Cytokines - blood; Female; HCV; Hepatitis C, Chronic - blood; Hepatitis C, Chronic - immunology; Humans; Male; Middle Aged
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2009.09.012

A body of evidence has suggested a close link between chronic hepatitis C virus (HCV) infection and B cell abnormalities, including mixed cryoglobulinemia, rheumatoid factor (RF) production, and lymphoproliferative disorders that may develop into non-Hodgkin’s lymphoma. Recent studies have demonstrated the expansion of CD5 + B cells in the peripheral blood of chronic hepatitis C patients (CHC). As CD5 + B cells, which are capable of producing autoantibodies and RF, are apparently crucial for the development of HCV-associated pathogenesis, the fate of both the CD5 + and CD5 − B cell subsets upon chronic HCV infection is of interest. In this study, the degree to which chronic HCV infection induces apoptosis in each B cell subset was investigated. Our results demonstrated that peripheral CD5 − B cells were more susceptible to apoptosis than CD5 + B cells in CHC. Furthermore, plasma levels of IL-4, IL-10, and IL-12 were significantly elevated in CHC, thus suggesting that these interleukins protect CD5 + B cells from apoptosis. The rationale for the differential susceptibility of distinct B cell subsets in CHC is also discussed with regard to extrahepatic manifestations associated with chronic HCV infection.